Research

Exercise is Good for You, but Can it Help You Stop Drinking?

The benefits of exercise for physical and mental health are well documented. Can it help people reduce or quit drinking too?

WHAT PROBLEM DOES THIS STUDY ADDRESS?

There are health and mental health benefits to aerobic exercise. The effects of exercise on depression, for example, often can be just as good for some as with antidepressant medications. Also, there is overlap between substance use and other psychiatric disorders in terms of what is happening in the brain (e.g., both substance use disorder and major depressive disorder are associated with impairments in the reward circuity). So, it makes sense that exercise may also be helpful for substance use disorder. A prior review specifically investigating whether exercise interventions can help address alcohol use disorder found mixed results on drinking and related symptoms such as anxiety and mood. In this study Hallgren and colleagues performed a meta-analysis – a combined review and analysis of many studies– to shed further light on exercise for alcohol use disorder.

HOW WAS THIS STUDY CONDUCTED?

The authors used a systematic search process to identify all studies through April 2016 that tested both acute (a single session) and long-term (2 weeks or more) exercise interventions against a comparison group over time. They excluded any cross-sectional studies (measuring only one point in time) and prospective-observational studies (measuring a single group over time). They defined exercise as “a planned repetitive movement purposefully engaged in to improve fitness and/or health”. Drinking was measured by standard drinks per day or heavy drinking days (while not defined in the paper, the US Substance Abuse and Mental Health Services Administration, or SAMHSA, defines heavy drinking as five or more drinks for men or four or more for women on one occasion, 5 days in the past month).

WHAT DID THIS STUDY FIND?

The authors systematic search resulted in 21 articles that met their criteria, including four studying acute exercise and 17 long-term exercise, that included a total of 1202 individuals (median sample size was 34 participants). For the vast majority, exercise was generally tested as an add-on to an “active” comparison like cognitive-behavioral therapy or medication. Most of the exercise interventions consisted of aerobic exercise (13), five a combination of aerobic, strength training, and stretching, and three tested yoga.

Individuals receiving exercise interventions did no better than comparison groups on both drinking outcomes – drinks per drinking day and heavy drinking days – though they were no more likely to drop-out of treatment either. Confidence in their ability to abstain from alcohol or “abstinence self-efficacy” was also found to increase the same amount. As one example of a study that was analyzed in their meta-analysis, Brown and colleagues conducted a randomized controlled trial that tested an intensive, 12-week exercise intervention, that included adjunctive group sessions and financial incentives to encourage exercise participation, and compared it to a brief advice intervention that encouraged people to exercise. They found that the patients assigned to the exercise intervention had a lower likelihood of any drinking as well as any heavy drinking at the end of the intervention (12 weeks), but this advantage disappeared – the groups were equal – 12 weeks after completing the intervention.

Their similar rates of staying in treatment is important because those assigned to exercise interventions experienced reduced depression symptoms and improved physical fitness – but similar anxiety. Despite this, however, this reduction in depression symptoms did not lead to reductions in alcohol use.

WHY IS THIS STUDY IMPORTANT

Since harmful drinking is among the greatest risk factors for disease, disability, and premature mortality in the U.S. – accounting for 88,000 deaths a year – it is important to identify simple, convenient activities that can help reduce drinking, in which anyone can engage, no matter their access, ability, or willingness to seek professional help. Also while many professional treatments are helpful, even the “best” treatments are limited in one way or another – and self-management techniques to improve professional outcomes are needed. This study found that, on the whole, exercise interventions do not help reduce drinking more than comparison interventions.

One important finding though, is that people were as likely to stay in treatment when receiving the exercise intervention. At the same time, exercise helped decrease individuals’ depression and improve their physical fitness. So engaging in exercise is unlikely to do harm when it comes to someone’s substance use, and may help them in other important areas of health and well-being. This suggests exercise interventions are worth trying, at a minimum, for individuals with alcohol use disorder.

One lingering question is what is the best type of exercise intervention. As summarized above, for example, in the study by Brown and colleagues which showed a positive effect of exercise early on, the exercise intervention was fairly involved, including structured exercise classes, groups to help increase motivation to exercise, and rewards for exercising (i.e., contingency management).

One important question to ask is: “To what are the exercise interventions being compared?” In this case it was almost in all cases an add-on to standard treatment, often an evidence-based treatment. That treatment may not be able to help beyond the help already provided by that treatment. On the other hand, it is possible that exercise might be helpful to alcohol outcomes for individuals who are not receiving treatment, where even a small amount of help could be a meaningful boost above no treatment at all.

There is increased interest in the benefits of exercise for individuals with alcohol and other drug use disorder (i.e., substance use disorder) – also see, for example, this study on methadone maintenance patients who researchers engaged with a videogame-based exercise intervention, and this study investigating exercise for individuals in residential treatment for methamphetamine use disorder. Rigorous studies are needed to understand how to engage both addiction treatment patients and individuals in the community with exercise interventions, which types of exercise are most helpful, and the effects of the interventions on substance use outcomes, as well as other mental and physical health outcomes.

Understanding the direct and indirect ways in which exercise helps could also be important. It could be that there are direct physiological effects on brain and body which helps mitigate relapse risk; but it may also be equally possible that engaging in physical activities with other recovering individuals (e.g., team sports or group yoga) could facilitate competing pro-social engagement that could lead to the adoption of new sober lifestyles. For example, Phoenix Multisport is an organization that engages people in group-based physical activity to help enhance their recovery-supportive social networks and activities. The recovery-related effects of participating in this type of organization warrant further investigation.

LIMITATIONS

In systematic reviews like these, authors seek to determine the scientific rigor of the studies – to be able to tell whether the intervention caused the changes they observed. In this study, all studies had either “high” or “unclear” risk of bias, suggestive of low or unclear scientific rigor. Given the promise of exercise interventions, but limited scientific rigor of the studies to date overall, more rigorous tests of interventions are needed to help clinicians, policy makers, and lay individuals learn whether, and in what ways, exercise is helpful for those with substance use disorders.

NEXT STEPS

One urgent next step is to develop and test exercise interventions for adolescents and young adults with substance use disorder. There are reasons to believe exercise is a helpful and engaging activity for youth, but formal research is needed.

BOTTOM LINE

For individuals & families seeking recovery: For people with alcohol use disorder, exercise is likely to help improve physical fitness and to reduce depression symptoms. It appears unlikely to make a difference in general in terms of drinking outcomes, at least in the short term. Because it seems to be helpful for many other reasons that are important on their own, and may indeed impact drinking over the long-term (though more research is needed), aerobic exercise is a good idea for people in, or seeking, alcohol use disorder recovery.

For scientists: For people with alcohol use disorder, exercise may help improve physical fitness and possibly mental health symptoms like depression. This meta-analysis showed it is unlikely to make a difference in terms of drinking outcomes, at least in the short term. Given exercise may improve health outcomes that might reasonably help support recovery down the road (e.g., reduced depression), one next fruitful step may be to examine long-term outcomes in response to exercise, and tap into what aspects of exercise may be helpful to substance outcomes, for whom they may be helpful, and through what mechanisms they aid recovery.

For policy makers: For people with alcohol use disorder, exercise is likely to help improve physical fitness and likely aspects of mental health like depression. This meta-analysis showed it is unlikely to make a difference in terms of drinking outcomes, at least in the short term. Given how easily disseminable exercise recommendations can be, and the immense burden of alcohol use disorder on health, criminal justice, and financial systems in the U.S., funding for research on exercise for individuals with substance use disorder is likely to yield key information to inform treatment and other health recommendations.

For treatment professionals and treatment systems: For people with alcohol use disorder, exercise is likely to help improve physical fitness and to reduce depression. It may not make a difference, in general, in terms of drinking outcomes, at least in the short term. Because it seems to be helpful for many other reasons that are important on their own, and may indeed impact drinking over the long-term (though more research is needed), treatment program staff may wish to recommend aerobic exercise for their patients in, or seeking, alcohol use disorder recovery. Engaging in exercise as a potentially fun and pro-social activity with other recovering people may lead to positive social engagement that may facilitate recovery through a psychosocial rather than biological pathway.